West Nile Virus in San Diego County

West Nile virus (WNV) is a disease transmitted to humans, birds,
horses, and other animals, by infected mosquitoes. Mosquitoes get the
disease from feeding on infected birds and can later pass it on when
they bite animals or humans.

WNV is established in San Diego County and can be found in all 58
counties in California! The virus was first isolated in the West Nile
district of a Northern Province in Uganda in 1937. It was first
detected in the United States in New York City in 1999. From there,
the virus spread westward, arriving in California in 2003. West Nile
virus is now the most prevalent mosquito-borne disease in the United States.